Combretastatins and their analogues: Nature as an alternative source for the therapy of cancer

Abstract

Since the identification and characterization of chemical constituents from african tree Combretum caffrum species, it took more than three decades. Among these C. caffrum components, combretastatin A-4 showed highlighted antineoplastic, cytotoxic and antiangiogenic profile. Its reduced bioavailability linked to its limited pharmacokinetic profile has encouraged the scientific community to propose chemical modifications in the structure of this natural product in order to overcome these limitations and to obtain therapeutically relevant compounds. In this paper we describe aspects of the structure- antitumoral activity relationships of combretastatin A-4 analogues proposed by the introduction of changes in its subunits A, B and spacer.